Traction brake and driving mechanism



May 25, 1943.

H. E. BREY ETAL 2,320,320

TRACTION BRAKE AND DRIVING MEGHANISM Original Filed May 29, 1941 5 Sheets-Sheet l May 25,1943. H. E. PQEY ETAL 2,320,320

TRACTION BRAKE AND DRVNG MECHANISM Original Filed May 29, 1941 5 Sheets-Sheet 2 May 25, 1943. H. E. BRI-:Y ETAL TRACTION BRAKE AND DRIVING MEQHANISM Original Filed May 29, 1941 5 Sheets-Sheet 3 Tm/amiss. Harald Efrqg Hdber'ZfZ/fa/wm,

3m fa/zig; mi,

May 25, 1943. H. E. BRI-:Y ErAL 2,320,320

TRACTION BRAKE AND DRIVING MECHANISM Original Filed May 29, 1941 5 Sheets-Sheet 4 May 25, 1943. H. E. BREY ETAL 2,320,320

TRACTION BRAKE AND DRIVING MECHANISM 4 Original Filed May 29, 1941 5 Sheets-Sheet 5 Patented May 25, 1943 TRACTION BRAKE AND DRIVING MECHANISM Harold E. Brey. Wauwatosa, and Hilbert E.

Swanson,-ltiilwaukee, Wis., assignors to Universal Unit Power Shovel Corporation, West Allis, Milwaukee, Wis., a corporation oi Delaware Original application May 29, 1941, Serialv No. 395,704. Divided and this application March 13, 1942. Serial No. 434,546

2 Claims. (Cl. 18o-9.2) This invention relates in general to improvements in traction brakes, and while it has more particular reference to a driving and braking mechanism, it will be apparent that certain features have other and more general and valuable application. The present invention is a division of our co-pending application Serial No. 395,704, filed May 29, 1941.

A principal object of the invention is the pro- In the drawings,

Figure 1 is a transverse sectional view taken approximately at the center of a power shovel embodying. the features of this invention;

Fig. 2 is an enlarged and fragmentary view, half in the bottom plan and half in diametrical section, of the driving mechanism for the traction means of the power shovel shown in Figure Figure 3 is a fragmentary view, with portions vision of a new and improved driving and braking l mechanism. in section, of the traction means driving mecha- An important object of, the invention is the nisrn, drawn to the same scale as Fig. 2 and taken provision of a new and improved brake device looking forward from the back of Fig. 1; particularly adapted for use in a combined driv- Fig. 4 is an enlarged transverse sectional view ing and braking mechanism. l5 taken approximately along the line 4-4 of Fig. 1,

Another important object of the invention is showing the brake in applied position. Y the provision of an automatically operable brake Fig. 5 is a view similar to Fig. 4, but showing device which serves as a positive friction type the brake in released position; device locked or engaged under normal condi- Fig. 6 is an enlarged and partially sectional tions. 20 detailed view showing the actuating means for A further important object of the invention the brake shoes; is the provision of a brake device which is nor- Fig. "I ls a detailed view of the brake actuating mally in engaged position and which automatishaft; cally releases with the application of driving Fig. 8 is a transverse sectional view taken appower to the element being braked. 35 proximately along the line 8-8 of Fig. 3 and Another object of the invention is the provishowing the brake in applied position; sion, in a mechanism having a pair of driving Fig. 9 is a view similar to Fig. 8, but showing elements and a combined driving and braking the brake in released position; unit for each element, of an automatically and Fig. 10 is a fragmentary transverse view taken independently operable brake for each unit of the along the line lll-l0 of Fig. 3, and showing the mechanism, the brake being normally applied brake in applied position; and and released as an incident to the application of Fig. 11 is a view similar to Fig. 10, showing driving power to the unit. the brake in released position.

A further object of the invention is the provi- It will be understood that while the invention sion, in a mechanism having a pair of driving .".5 is adaptable for use in a variety of machines, elements. of a normally applied and independor vehicles, it is. for purposes of disclosure,

- ently operable brake mechanism for each element shown in the drawings and hereinafter described and means for applying driving power t0 the in detail as embodied in the traction means of elements simultaneously or separately, the brake a power shovel, Generally, such a power shovel mehanism 2111150111aticalli' releasing the element 40 has a pair of crawlers or caterpillar treads 20 Pm the application 0f driving POWER and 2| vdisposed one on each side of the shovel A further object of the invention is the proviand each guided on a suitable track usually com- Sion- .1 a machine having traction means of the posed of rollers 22 journaled in a suitable frame, caterpillar or crawler type, of a b rakemechanism herein generally indicated at 23 Mounted upon fqr .each nach@ element .Whlch 1S normany 4" the crawler frame 23 and preferably rigidly seapphed .ani Whufm autmsaaly rleasels mu; cured thereto, as by welding, is a frame 24 which a; elfment is driven might be considered as completing the chassis Numerous other objects and advantages of the of the power shovel, This lower frame includes invention will be apparent as it is understood a central' hub 25 of substantial diameter? an from the following description, which, when annular channel shaped member 26 providing taken in connection with the accompanying an outwardly Opening 1'01181 track. and large drawings, discloses a preferred embodiment internal gear 2T integral With the Channel memthereof. ber 26.

Mounted upon the lower frame 2@ for rotation relative thereto is a rotating frame, generally indicated at 28, which forms the base oi' the shovel superstructure consisting of the boom, the cab, the motor M and the various gearings, clutches and control levers for operating the boom, drag line and the rotation of the rotating frame. These parts are all well-known construction and form no part of this invention and hence are not herein described in detail. Accordingly it would seem sufficient to point out that the rotating frame 23 has formed therein an elongated journal housing 29 which is journaled in the hub 25 to center the rotating frame, but which does not support the rotating frame, such support being obtained through rollers 33 carried by the frame and operating in' the roller track formed by the member 23.

Each crawler is adapted to be driven independently by means including a drive element 3 I, in the form of a sprocket, from a drive shaft 32 extending transversely of the lower frame and journaled at 24' in the lower frame. Non-rotatably xed on the shaft 32 intermediate the ends thereof, as by a key 33, is a bevel gear 3l meshing with a bevel gear- 35 non-rotatably mounted on the lower end of a pintle 33 journaled at 31 and 33 in the journal housing 29 of the rotating frame. At its upper end the pintle 33 has rotatably mounted thereon a spur gear 39 having one face thereof formed with teeth or jaws III so as to constitute one element of a clutch, the complementary element 4I of which is spiined to the pintle 36. The gear 39 meshes with the spur portion -42 of a compound gear 43 driven through suitable gearing by the motor M. Lever mechanism, generally indicated at M, is operable to shift clutch element 4| longitudinally of the pintle for connection of the pintle with the motor;

In a variety of mechanisms to which this invention is applicable but particularly in traction means of the crawler type, provision must be made to drive both crawlers either forwardly or backwardly simultaneously, or to drive one crawler only in either direction while the other crawler is held stationary. To hold one of the crawlers stationary while the other crawler is operating, a variety of brake devices have been employed. These devices have, however, all proved unsatisfactory for a variety of reasons, but primarily because of the fact that their application or release required the. attention of the operator of the power shovel. It is a feature of this invention to include in the driving mechanism for the crawlers automatically operable brake mechanism requiring no attention on the part of the operator. More particularly, brake mechanisms are provided which are normally engaged, thereby guarding against 'possible runaway of the shovel, the brake mechanisms being automatically released as an incident to application of power for driving the crawler.

Interposed operatively between the drive shaft 32 and one of the sprockets 3l is a brakingland driving unit, generally indicated at 50, and o'peratively interposed between the drive shaft 32 and the other sprocket 3| is a similar braking and driving unit 5I. These units are identical in construction, hence only one will be described. Each of the units comprises an elongated sleeve I2 rotatably mounted on an end of the shaft 32 on bushings 53 and 54. At its outer end the sleeve 52 has non-rotatably secured thereon, one of the sprockets 3 I, while at its inner end the sleeve is formed with a pair of axially spaced radially projecting anges il@ and El extending partially around the sleeve and reinforced by webs Sil connected therebetween Projecting axially inwardly from the face of the innermost flange 51 are a pair of clutch Jaws or teeth .59 and a pair of Jaws 59'. The Jaws are spaced to provide three equal spaces therebetween each being considerably wider than even a full jaw or tooth 59.

Extending radially outwardly from this flanged end of the sleeve 52. so as to lie between the jaws 39' as viewed in Figs. 4 and 5, are a pair of ears 39 (see Fig. 6) disposed in planes transversely of the sleeve 52 and spaced axially. The sleeve is cut away at 9i radially inwardly of the ears ll, as best seen in Fig. 2', for a purpose which will presently become apparent. Intermediate the flange 56 and the splined end, the sleeve is somewhat reduced in external diameter and is lournaled in a bearing 32 formed by the lower frame 24.

Disposed concentrally with the shaft 32 and sleeve 52 in the plane of the inner flanged end of the sleeve is an annular ring 63, the inner periphery of which constitutes a brake drum. 'I'his ring preferably is formed with outwardly projecting ears 34 diametrically disposed, by means of which the ring is rigidly secured to the lower frame 24 by means such as bolts 95. Cooperating with the ring 33 are a pair of brake shoes 99 and I1, each approximately scmicircular and carrying the usual brake lining 63. The shoes are of identical construction, each having a band I9 and aradial reinforcing flange 10 to give the shoe intermediate its ends a generally T-shaped cross section. At one end, hereinafter termed the connected end, the :flange 10 is expanded to produce a box-like structure 'Il with an open top and bottom, and a front wall 12 having a slot 13 opening through the inner edge of the ange. Received in the box-like structure of the shoe 01, as shown in Figs. 8 or 9, is the head 14' of a bolt 'I4 with the bolt proper projecting through the slot 13. 'I'his -bolt is threaded into an internally threadedsleeve 1i which has a reduced portion 19 spaced inwardly from one end to form a head 11 which is received in the box-like portion of the shoe Si, the reduced portion 'Il lying in the slot 13. Also threaded on the bolt 14 is a lock nut 13 by means of which the sleeve and the bolt are locked in the desired position of adjustment. The inner face of each wall 'I2 and the wall opposite it are preferably made slightly convex, as

best seen in Figs. 8 and 9, to provide bearing points for the shoes against the sleeve and the bolt. A pin 19 preferably extends across the top of each box-like structure to prevent the sleeve or bolt, as the case may be, from dropping out.

Near the opposite end the flange 1l is expanded into a cup-like portion 33 to provide a socket Il (Figs. 8 and 9) for the reception of one end of a compression spring 33 extending transversely of the shaft 32 between the shoes 63 and 91. From th cup-shaped portion outwardly to the end. the flange continues in its expanded form but becomes solid while the band is narrowed to form a control head 33 (see Fig. 6) receivable between the ears 3l. I'his head is divided centrally to provide a toreshortened portion 31 and an extending portion 38. 'I'he extending portion I3 takes the form of a yoke with an arm 33 and an arm 99 spaced .radially outwardly oi the arm 39. Extending portion 81 also has a reduced radial dimension so as to be receivable between the arms 89 and 90 of the other shoe; it being readily apparent and as best seen from Fig. 6, that the heads 86 dovetail in the assembled position of the shoes.

With the brake shoes 66 and 61 urged apart and outwardly, by the compression spring 85, into engagement with the brake drum formed by the inner surface of the ring 63, the brake mechanism is normally applied unless disengaged or released by the actuation of means provided for that purpose. The brake releasing means shown herein comprises a shaft 93 journaled in the ears 50 and projecting through the yoked portions 88 of the control heads 86. Preferably interposed between the shaft and the ears are bushings 94. The shaft is formed (see Fig. 7) with a pair of parallel axially spaced, transverse and cord-like grooves 95 cut into the shaft on diametrically opposite sides. These grooves each receive therein one of the bolts 9|. It will be apparent from Figs. 6 and 8 to ll that, because of. the extending portions 88, the bolts 9| will lie on that side of the shaft 93 opposite the shoe carrying the bolt.

As best seen in Figs. 8 and l0, the grooves 95 in the shaft 93 are deep enough so that there is ample clearance. permitting the brake shoes to fully engage the ring 63. Likewise, there is ample clearance between the bolt and the bottom of the yoke of the extensions 88 to permit releasing or disengaging movements of the brake shoes. It will be clear that. with these clearances, and with the bolts 9| on the side of the shaft 93 opposite the shoe carrying them, rotation of the shaft l 93 will through cam action cause separation of the bolts 9| and hence disengagement of the brake shoes from the ring 63. Such release of the brake occurs whether the shaft is rotated counter-clockwise, as shown in Fig. 9, or clockwise, as shown in Fig. 1l. As the bolts 9| are separated, the heads 86 are drawn together, drawing the foreshorfened portion 81 toward the extending portion 88 of the opposite shoe, and hence toward the bolt 9| carried by that extending portion. To accommodate the bolt, the foreshortened portion is formed with a radially extending groove 96.

Means are provided herein for driving the sleeve 52 and for releasing the brake mechanism with the application of power to the sleeve 52. This means comprises an elongated sleeve non-rotatably mounted on the shaft 32 by suitable means such as a key im. This sleeve forms one element of a clutch, generally indicated at`99, and to that end is formed with a radial flange |02 providing clutch jaws or teeth |03. Surrounding the sleeve |00 is a bushing |04, and both rotatable and axially slidable relative to the sleeve |00 is a sleeve forming a compound shiftable clutch element. At its inner end,.the sleeve |05 is formed with clutch jaws or teeth |06 for interengagement with the teeth |03 of the sleeve |00. At its other or outer end, the sleeve |05 is formed with three clutclrjaws or teeth |01 received between the teeth 59, 59 of the sleeve 52. The length of the jaws 59, 59 and |01 is such that they remain meshed in either position of the sleeve |05, that is, with the clutch 99 engaged or disengaged.

The jaws |01 are of approximately the same width as the jaws on the sleeve 52 and are thus considerably narrower than the spaces between the jaws of sleeve 52. Hence there is considerable lost motion between the sleeves 52 and |05 even -and 11.

though their jaws are meshed. This lost' motion is utilized to release the brake prior to engagement of the jaws |01 with the jaws 59. so that at the time power is transmitted to the sleeve 52 the brake mechanism isdisengaged and the sleeve 52 freed to rotate. To that end. the shaft 93 has secured on one end thereof a tapering arm or finger |08, while the sleeve |05 is opposite the intermediate one of the jaws |01 formed with a pair of lip-like teeth |09 between which the end of the finger |08 is received.

It is believed that it will be apparent from the foregoing that the action of the spring will apply the brake, mechanism, and that in so doing, it will through the bolts 9| rotate the shaft 93 to the position shown in Figs. 4, 8 and l0, which may be considered a normal or neutral position. Through the finger |06 the shaft will return the sleeve |05 to a normal or neutral position wherein the jaws |01 are positioned midway between adjacent jaws 59. Upon engagement of the jaws |03 and |06, and resultant rotation of the sleeve |05, the shaft- 93 will rst be rocked and thereby draw the brake shoes together to release the brake mechanism. By the time the jaws |01 engage the jaws 59, the brake mechanism will be fully released and the parts will be in the position shown in Figs. 5, 9 Figs. 5 and 9 show the position of the parts when the sleeve 05 is rotated in a clockwise direction, while Fig. l1 shows the parts in the position which they assume when the sleeve |05 is rotated in a counterclockwise direction` it being readily apparent, as previously pointed out,

that the shaft 93 is operable to release the brake regardless of the direction in which it is rocked away from its neutral position.

To provide for engagement or disengagement of the sleeve |05 with the shaft 32, so that the crawler associated with the particular unit may be driven or held'stationary, the sleeve 05 is formed with a groove ||2 which is engaged by followers ||3 carried by the arms of. a shifting fork ||4 rockably mounted on a pin ||5 supported in a portion of the lower frame 24. Projecting in a direction opposite to the arms of the shifting fork is an arm H6 terminating in a spherical end ||1 having the usual bore with flared ends passing therethrough.

The shifting forks ||4 for the units 50 and 5| are connected to he simultaneously actuated by the operator through a single control lever. To that end, there is `mounted in the cab a lever ||8 which has a neutral position on either side of neutral. This lever is connected by a link ||9 with one arm of a crank |20, the other arm of which is connected to a rod |2| extending Aaxially through the pintle 36. At its lower end. the rod |2| is connected to an arm |22 which is rigid, as best seen in Figs 2 and 3. with one end of a stub shaft |23. This stub shaft is journaled in a bracket |24 secured to a portion of the lower frame 24, and at its other end has rigid therewith a triple armed crank |25. One arm |25' nf this crank is connected to a rod or link |26 which is threaded at its free end and passes slidably through the spherical end ||1 of one of the shifting forks ||4. 0n opposite sides of the spherical end ||1 the rod |26 carries elidably thereon cup-shaped washers |21 and |28. and also carriers two sets |29 and |30 of lock nuts. Interposed between the set |30 of nuts and the washer |28 is a compression spring I3|. Connected to a second arm |25" of the crank |25 is a rod |32 which,` like the rod |26, is threaded and passes slidably through the spherical end H7 of the other shifting fork. The rod is connected to the shifting fork in the same manner as the rod |26. namely, through cup-shaped washers |21 and |28, sets of lock nuts |29 and |30, with a compression spring |3| again interposed between the washer |28 and the set 30 of lock nuts. The spacing of the sets of lock nuts coupled with the employment of the compression spring |3| whichl provides lost motion between the rods and the shifting forks, while at times tending to urge the sleeve |05 to engaged position, permits both the units 50 and 5| to be in driving engagement when the lever ||8 is in neutral position, or permits one or the other unit to be in driving engagement while the other unit is disconnected.

It will be seen from the drawings and more particularly Figs. 2 and 3 thereof, that when the lever ||8 is shifted to one side of its neutral position, the crank |25 is caused to be rocked in a clockwise direction. as viewed in Fig. 3, thereby causing the rod |26 through spring |3| and wisher |28 to shift the sleeve |05 into engagement with the jaws |03. Atthe same time, the rod |32, through the washer |21 and set |29 of lock nits, will shift the sleeve |05 of the unit 5| to disengaged position. Under these circumstances, the crawler driven from the unit 50 will be driven with the brake mechanism released through the action of the sleeve |05 on the shaft 93. 'I'he crawler driven from the unit 5|, however, will be held stationary by the brake mechanism which is applied at all times when no driving force is being transmitted from the shaft 32 to the sprocket 3|. Should the operator wish to have both crawlers operate simultaneously, the lever ||8 is shifted to its neutral position, thereby rocking the crank |25 in a counterclockwise direction, as viewed in Fig. 3, from the position shown in Fig. 3. Such movement of the crank |25 is suilicient to cause engagement of the sleeve |05 of the unit 5I with the jaws |03, but is insuilicient to disengage the unit 50. Thi: is possible, because in the position shown in Fig. 3 there is a clearance between the set' of nuts |29 on rod |26 and the spherical end sufficient to permit of this rocking of the crank |25 to neutral position without actuating the shifting fork H4. Ii' the lever ||8 is now shifted beyond neutral in the same directionI the crank |25 is rocked further in a. counterclockwise direction. With such movement, the nuts |23 will then cause disengagement of the unit 50 since the lost motion was taken up in Ithe `previous shift to neu-v tral. The further axial movement of the rod |32 is permitted even thoyfgh the sleeve |05 of the unit 5| was already in engagement with the teeth |03 by the compression of the spring |3I.

It is believed that it will be apparent from the foregoing that a unique and most advantageous combined driving and braking mechanism, which has ready application in a variety of fields has been provided. More particularly, unique means have been provided for any mechanism having a pair of elements which are to drive simultaneously or separately while the other element is held stationary, for example, traction means of the crawler or caterpillar type. With the instant construction, each crawler is locked at all times, thereby preventing the machine from running away should there be some break in the driving mechanism. More important, however, the conrelease of the brake mechanisms as an incident to the application of' power. This relieves the operator of the necessity of manually releasing the brake mechanisms, making the machine equipped with this traction means 4more readily manipulated and, above all, prevents the injury which results from application of power without release of the .brake mechanism, which occurs very frequently.

A It is thought that the invention and many of its attendant'advantages will be understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction l'and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing all of its materialv advantages, the form hereinbefore described being merely a preferred embodiment thereof.

We claim:

1. In a machine having a pair of traction members, driving mechanism for the traction members comprising a common drive shaft, a pair of rotatable elements to be driven from said shaft and each connected to one of the traction members, a brake mechanism for each of said elements normally applied to hold the same against rotation, a shiftable member for each element in all positions having a driving engagement with the element and operable` when driven to release said brake mechanis'rma clutch formed in part by each member forfcou'pling the member to said drive shaft, a shifting .yoke for each member, and manually operabl'control means for said last mentioned members comprising a rockable crank, a first link connected at one end to said crank and having a lost motion connection with one of said yokes, and a second link connected at one end to said crank and having a lost motion connection with the other of said yokes whereby the control means is operable simultaneously or independently to engage said clutches.

2. In a machine having a pair of traction members, driving mechanism for the traction members comprising a common drive shaft, a pair of elements to be driven from said shaft and each connected with one4 of the traction members, a brake mechanism for each of said elements normally appliedto hold the same against rotation. a shiftable member for each element in all positions having a driving engagement with the element and operable when driven to release said brake mechanism, a clutch formed in part by each member for coupling the member to said drive shaft, a shifting yoke for each member, and manually operable control means for said last mentioned members comprising a rockable crank, a first link connected at one end to said crank and having a lost motion connection with one of said yokes including yieldable means through which the member is urged toward clutch engaged position, and a second link connected at one end to said crank and having a lost motion connection with said other yoke including yieldable means for urging said member toward clutch engaged position, said control means in its neutral position causing both clutches toA be engaged, and on either side of its neutral position causing one of the clutches to be disengaged while the other clutch remains engaged with the yieldable means exing to permit the additional movement of the link.

HAROLD E. BREY. l

HILBERT E. SWANSON. 

